Many homeowners have security lights mounted on or near their home. Some of these lights are designed to turn on automatically if a motion detector is triggered and the ambient light level is low. These lights are a deterrent to burglary. Unfortunately, they can be easily defeated if the lamps are unscrewed or loosened either prior to the burglary or during the attempt.
In addition, if the lights are loosened by natural forces, such as vibrations from passing heavy trucks, etc., abrupt jarring motions, such as foundation loosening, machinary movement, sound, repetitive motions etc., then the lamps will also be loosened. Moreover, a loosened lamp would not be noticed during daylight hours.
Various attempts have been made to provide lamp failure devices. U.S. Pat. No. 5,099,177 of Taniguchi discloses a lamp circuit with disconnected lamp detecting device. U.S. Pat. No. 4,980,672 of Murphy discloses an overhead socket smoke detector with theft alarm.
U.S. Pat. Nos. 4,396,868 and 5,168,198 of Watanabe discloses a lamp circuit with disconnected lamp detecting device and a lamplight failure detection system respectively. U.S. Pat. No. 5,359,325 of Ford discloses an automatic monitoring system for airfield lighting systems.
Furthermore, U.S. Pat. No. 5,387,909 of Neel discloses a lamp sensing system for traffic light. In addition, U.S. Pat. No. 5,034,659 of Taniguchi describes a lamp circuit with a disconnected lamp detecting device. U.S. Pat. No. 4,700,126 of Hill shows a vehicular lamp circuit tester.
Moreover, U.S. Pat. No. 4,438,421 of Toyomura discloses an electronic device having a warning means and U.S. Pat. No. 4,295,079 of Otsuka describes a lamp circuit with a disconnected lamp detecting device. U.S. Pat. No. 4,422,068 of Helft discloses an intrusion alarm system for preventing actual confrontation with an intruder.
In addition, U.S. Pat. No. 3,975,627 of Huber shows a burglar-proof guard for light bulbs and U.S. Pat. No. 4,936,789 of Ugalde shows a method and apparatus for preventing the theft of a fluorescent lamp and ballast transformer.
Among other prior art includes U.S. Pat. No. 4,812,827 of Scripps which describes a detector and light assembly and U.S. Pat. No. 5,406,129 of Gilmartin which describes a flashing locator switch control with built-in lamp operation test.
While the prior art teaches a variety of methods for failed lamp detection and even an alarm for detecting removal of a smoke detector from a socket, the applications are very specialized. The present invention sets off an audible or silent alarm when an ordinary bulb or flood lamp is loosened or removed from the socket of a single or multi-lamp security light fixture. Furthermore, the alarm remains on or otherwise indicates that an incident had occurred even if the lamp is immediately retightened in its socket. This action is achieved using inexpensive switch elements and electronic subsystems consistent with the product cost limitations dictated by this consumer market.